I think the correct answer would be A. The type of congruence transformation for the preimage ABC to EDC would be a reflection. It is a transformation where you basically flip the preimage or the original shape ove a line which is called the line of reflection. So, the image would be a mirror image of the preimage. By plotting the points, you will see that triangle EDC is just a mirror image of triangle ABC and the line of reflection would be at x = 3. It could not be a rotation since the preimage was not turned or rotated around a center of rotation. Also, it cannot be a translation since the preimage was not just moved left, right, up or down.
You have to make sure that whatever you do to one side, you also do to the other.
2x + 37 = 8x + 7
2x + 37 - 2x = 8x + 7 - 2x
37 = 6x + 7
37 - 7 = 6x + 7 - 7
30 = 6x
30 / 6 = 6x / 6
5 = x
x = 5
Hope this helps! :)
Answer:
x=19
DE=84
EF=36
reasoning:
the sum of DE and EF is 120, so to find the value of each first you find x
find x by adding DE and EF
this gives you the equation (4x+8)+(2x-2)=120
combine like terms and get 6x+6=120
subtract 6 from both sides to get 6x=114
divide both sides by 6 to get x=19
plug 19 into x in both equations to get the values of each length
20 with a number minus what will equal 9. ^_^
